Exploring the Role of Sonication Fluid Culture in Periprosthetic Joint Infection: A Comparative Study with Conventional Methods.

Objective: The aim of this study is to evaluate and compare the diagnostic effectiveness of sonication fluid culture (SFC) compared to conventional methods in identifying the causative microorganisms in periprosthetic joint infections.

Methods: In this study, three cultures were evaluated for diagnosing periprosthetic joint infection intraoperative periprosthetic tissue culture, implant culture, and SFC. The sensitivity, specificity, and predictive values were calculated for each method, using the 2018 definition of periprosthetic hip and knee infection and clinical evaluation as references. Of the 92 patients who had implants removed, 49 were for mechanical reasons and 43 for infection.

Results: Positive cultures were obtained in 13 out of 49 patients with mechanical issues and 31 out of 43 with infections. The sensitivity of periprosthetic tissue cultures (53.5%) is slightly higher than SFC (48.8%), suggesting better detection of positive cases. However, SFC's specificity (83.7%) is higher, indicating more accurate identification of negative cases compared to periprosthetic cultures (73.5%). However, SFC identified additional pathogens in patients with negative periprosthetic tissue and implant cultures. Examination of the infected knee and hip prostheses showed that SFC enhanced pathogen detection, particularly in patients with negative implant cultures. Despite this, SFC was not statistically superior to other methods.

Conclusion: This study supports the combined use of periprosthetic tissue culture and SFC for identifying causative microorganisms in implant infections. Despite not being statistically superior, SFC provides additional pathogen detection, especially when other methods fail, thereby enhancing overall diagnostic accuracy.